1. Field of the Invention
The present invention relates to an apparatus used to suppress or prevent a blur generated due to, e.g., a camera shake.
2. Related Background Art
Conventional anti-vibration apparatus for suppressing or preventing a blur of a camera may include a sensor (e.g., a vibration gyro) which detects the vibration amount of a camera main body. In accordance with an output from the sensor, a correction optical system movable in an x-y plane perpendicular to the optical axis is driven, thereby suppressing or preventing a blur generated due to the camera shake of a photographer.
However, the sensor used in a conventional anti-vibration apparatus of this type is constituted by very small mechanical components, as represented by a vibration gyro. Because of this structure, an error signal different from an original sensor signal is undesirably generated due to a large impact such as a mirror shock or shutter shock in the camera.
A blur of a camera, which is generated due to a mirror-up or shutter running operation, has a very high frequency, and a currently available blur sensor cannot accurately detect a blur of a camera at such a high frequency.
Even when a blur of a camera at a high frequency can be detected, a phase delay is generated in a blur correction system upon correction of a blur at a high frequency of 100 Hz or more. Since the blur correction system cannot, therefore, sufficiently follow the blur, blur correction cannot be accurately performed.
In addition, a mirror or shutter blur changes depending on whether the camera is supported by a user or by a tripod. When a blur correction apparatus is incorporated in an interchangeable lens for a single-lens reflex camera, the blur also changes depending on the type of camera attached to the lens.
When an error signal different from an original blur is output, the correction system is driven in accordance with the output. For this reason, the operation of the anti-vibration apparatus sometimes undesirably causes an increase in blur.